Apply the grid method to each situation.

a. Calculate the energy in joules used by a 13 hp pump that is operating for 410 hours. Also, calculate the cost of electricity for this time period. Assume that electricity costs $0.20 per kWh.

b. A motor is being used to turn the shaft of a centrifugal pump. Apply Eq. (7.3b) to calculate the power in watts corresponding to a torque of 850 lbf∙in. and a rotation speed of 1100 rpm.

c. A turbine produces a power of 3500 ft ∙lbf/s. Calculate the power in hp and in watts.